1. Field of the Invention
The present invention relates, in general, to a floor covering based on perforated PVC (polyvinyl chloride) sheet, and in particular, to a floor covering based on perforated PVC sheet, in which a surface material such as wood or Korean paper is attached to a upper side of a high density perforated PVC sheet.
2. Description of the Prior Art
A demand for a PVC floor covering, in which a wood surface layer is attached to a PVC sheet, has been growing as high quality architectural interior finish having appearance and feel of wood. However, the PVC floor covering has disadvantages in that the PVC sheet has a different thermal expansion coefficient from the wood layer, and so a surface of the floor covering is not smoothly maintained owing to cracks or curling of the surface.
To avoid the above disadvantages, Korean Laid-open Publication No. 1998-047176 discloses a grained timber PVC floor covering, in which a back sheet is attached to a lower side of a high density PVC sheet, or non-woven fabric is inserted between a grained timber and the PVC sheet, and joined. However, this conventional invention has disadvantages in that an effect of preventing cracks or curling of the surface is not sufficient because the grained timber PVC floor covering does not sufficiently offset shrinkage or expansion differences between the grained timber and the PVC sheet due to use of a back sheet or non-woven layer, and that cracks or curling of the surface are not prevented because shrinkage or expansion differences between the grained timber and the PVC sheet are not offset in the PVC sheet.